Warping sprue plate....

[55BoysATR]

The sprue plate on a Lee 2-banger begins to lift up as it gets on the hot side, if I let it cool down just a tad, it straightens back out. Lifts up just enough to get some finning between the plate & mold. At first I though it was a bit of lead buildup from opening the mold too early ans getting a smear of lead across the top. If I let it cool down a bit, it straightens back out.

Anyone else had this happen???

[DLCTEX]

The plate should not warp as the metal is heated evenly when casting, but if there are some inclusions in the metal it may be acting like a bi-metal strip. I would try tightening and/or loosening the sprueplate screw.

[Shiloh]

Or changing the sprue plate if tweaking the hold screw doesn't work. Never had one warp when heated.

Shiloh

[55BoysATR]

Well I tried to get the plate off last night..... Couldn't get it loose. Soaking in Kroil.

[462]

Igor, Lee's 400-pound sprue plate screw installer, tightens the screw until it starts to smoke, then backs it out a quarter turn.

I don't think Kroil will help.

Put the mould in a padded vise and tighten it down just enough to hold it in place. Using the correctly sized Phillips screwdriver and applying plenty of downforce, it'll come loose. Afterward, the screw will have a tendency to work loose, so you will need to install an 8-32 set screw. Search "Lee-menting".

[MiHec]

Tap on screw few times. It is old mechanic trick....

[hiram]

Loosening wasn't too difficult for me when the mold was hot. I think the aluminum block expanded more than the steel screw and lessened the grip.

[JIMinPHX]

I can't remember who, but somebody on this board once recommended putting a Philips head screwdriver bit in a drill press & using the down force of the drill press to hold the bit tight in the screw head while turning the drill chuck. That has worked better than any other method that I have tried for removing the screw from a Lee sprue plate. Those self tapping screws sure do bite in there tight.